Research Projects

Geoglyphs

The unexpected discovery of
immense geometrically patterned earthworks called "geogphyhs" among the terra
firme rainforests of western Amazonia is radically changing our notion of past
human societies in this region of the Amazon.Over 300 of these spectacular geometric earthworks have been found
across eastern Acre state, Brazil.Prior
to the onset of large-scale deforestation in the 1980s, Acre state was
completely blanketed by terra firme humid rainforest, assumed by most
tropical ecologists to be pristine or virgin.Only after large-scale deforestation, did these previously hidden
earthworks become visible.These
earthworks comprise circles, squares, and other geometric shapes, between 90
and 300 m diameter.Most occur on
inter-fluvial uplands atop a 150 - 200 m plateau.Their purpose, and scale of environmental
impact associated with their construction, is still debated. Funded by National
Geographic Society and in collaboration with archaeologist Denise Schaan we have started a project to investigate what was the past
impact of the "Geoglyph Builders" on this region of Amazonia and what is the modern legacy of
their ancient land use. To tackle these questions we are using a multi-proxy approach,
combining analyses of pollen, phytoliths, stable carbon isotopes, and charcoal,
from radiocarbon-dated soil profiles and lake sediments from eastern Acre, which will be able to capture the rise
and fall of the "Geoglyph-Building" culture.